| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Trace verbosity level filtering."><meta name="keywords" content="rust, rustlang, rust-lang, level_filters"><title>tracing::level_filters - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc mod"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../../tracing/index.html"><div class="logo-container"><img src="https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/logo-type.png" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../tracing/index.html"><div class="logo-container"> |
| <img src="https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/logo-type.png" alt="logo"></div></a><h2 class="location"><a href="#">Module level_filters</a></h2><div class="sidebar-elems"><section><ul class="block"><li><a href="#structs">Structs</a></li><li><a href="#constants">Constants</a></li></ul></section></div></nav><main><div class="width-limiter"><nav class="sub"><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn">Module <a href="../index.html">tracing</a>::<wbr><a class="mod" href="#">level_filters</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../../src/tracing/level_filters.rs.html#1-94">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Trace verbosity level filtering.</p> |
| <h2 id="compile-time-filters"><a href="#compile-time-filters">Compile time filters</a></h2> |
| <p>Trace verbosity levels can be statically disabled at compile time via Cargo |
| features, similar to the <a href="https://docs.rs/log/latest/log/#compile-time-filters"><code>log</code> crate</a>. Trace instrumentation at disabled |
| levels will be skipped and will not even be present in the resulting binary |
| unless the verbosity level is specified dynamically. This level is |
| configured separately for release and debug builds. The features are:</p> |
| <ul> |
| <li><code>max_level_off</code></li> |
| <li><code>max_level_error</code></li> |
| <li><code>max_level_warn</code></li> |
| <li><code>max_level_info</code></li> |
| <li><code>max_level_debug</code></li> |
| <li><code>max_level_trace</code></li> |
| <li><code>release_max_level_off</code></li> |
| <li><code>release_max_level_error</code></li> |
| <li><code>release_max_level_warn</code></li> |
| <li><code>release_max_level_info</code></li> |
| <li><code>release_max_level_debug</code></li> |
| <li><code>release_max_level_trace</code></li> |
| </ul> |
| <p>These features control the value of the <code>STATIC_MAX_LEVEL</code> constant. The |
| instrumentation macros macros check this value before recording an event or |
| constructing a span. By default, no levels are disabled.</p> |
| <p>For example, a crate can disable trace level instrumentation in debug builds |
| and trace, debug, and info level instrumentation in release builds with the |
| following configuration:</p> |
| <div class="example-wrap"><pre class="language-toml"><code>[dependencies] |
| tracing = { version = "0.1", features = ["max_level_debug", "release_max_level_warn"] }</code></pre></div><h3 id="notes"><a href="#notes">Notes</a></h3> |
| <p>Please note that <code>tracing</code>’s static max level features do <em>not</em> control the |
| <a href="https://docs.rs/log/"><code>log</code></a> records that may be emitted when <a href="https://docs.rs/tracing/latest/tracing/#emitting-log-records"><code>tracing</code>’s “log” feature flag</a> is |
| enabled. This is to allow <code>tracing</code> to be disabled entirely at compile time |
| while still emitting <code>log</code> records — such as when a library using |
| <code>tracing</code> is used by an application using <code>log</code> that doesn’t want to |
| generate any <code>tracing</code>-related code, but does want to collect <code>log</code> records.</p> |
| <p>This means that if the “log” feature is in use, some code may be generated |
| for <code>log</code> records emitted by disabled <code>tracing</code> events. If this is not |
| desirable, <code>log</code> records may be disabled separately using <a href="https://docs.rs/log/latest/log/#compile-time-filters"><code>log</code>’s static |
| max level features</a>.</p> |
| </div></details><h2 id="structs" class="small-section-header"><a href="#structs">Structs</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LevelFilter.html" title="tracing::level_filters::LevelFilter struct">LevelFilter</a></div><div class="item-right docblock-short">A filter comparable to a verbosity <a href="../struct.Level.html" title="Level"><code>Level</code></a>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ParseLevelFilterError.html" title="tracing::level_filters::ParseLevelFilterError struct">ParseLevelFilterError</a></div><div class="item-right docblock-short">Indicates that a string could not be parsed to a valid level.</div></div></div><h2 id="constants" class="small-section-header"><a href="#constants">Constants</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.STATIC_MAX_LEVEL.html" title="tracing::level_filters::STATIC_MAX_LEVEL constant">STATIC_MAX_LEVEL</a></div><div class="item-right docblock-short">The statically configured maximum trace level.</div></div></div></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="tracing" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
